In Wilfred Owen's "Dulce et Decorum Est," the first images are that of the bodies of the men on the battle field, struggling to remain safe, fighting to stay alive, or dying under the frightening circumstances of war. The author's purpose in using them seems to be directly related to the obscenity of the lie propagated in the poem's title:
It is sweet and right.
While this sentiment might comfort or intrigue those at home in parlors and across well-set dinner tables, the truth included nothing fit for polite society: neither sweet nor right.
First the struggling men are described "like old beggars," as they drag themselves through the mud, many without boots on their feet. The men march as if they are asleep, pushed by automatic response. They are covered in blood, "drunk with fatigue," hardly able to see, to walk or even hear mortar fire flying over their heads. Their destination is "distant rest," though for some of these men, it will not be a bed in which they rest, but the arms of death.
Suddenly they are attacked with the green, noxious, deadly gas released by their enemies, and they struggle to protect themselves:
Gas! Gas! Quick, boys! — An ecstasy of fumbling,
Fitting the clumsy helmets just in time.
Failure to get the helmets on in time means certain death. Owen describes one such desperately unfortunate victim of the gas...
...flound'ring like a man in fire or lime**...
He can only see the man dimly, through the "misty" glass of his gas mask, surrounded by "thick green light" of the gas. It's as if the man is drowning is a "green sea." Owen cannot forget the scene: he sees him dying in his dreams, while he was unable to help.
This horrible death provides the main images—the gas travels into his lungs, while the man is...
...guttering, choking, drowning.
And Owen recalls all they could do was to throw the man onto a wagon as the life oozed out of him...
...the whites of his eyes writhing in his face...
...at every jolt, the blood
Come gargling from the froth-corrupted lungs,
Obscene as cancer...
Owen notes that only one who had watched this man suffer and die, only one who had followed the wagon frightened and appalled by the gas's unholy effects on the human body, only a man who had survived and still dreamt of the horror could comprehend "[t]he old Lie."
"Lie" is capitalized, stressing the significance of the word—for had a person at home seen these things, he would not continue to glamorize the war and the sacrifice of the men, while tucked away at home in safety at gentle distance. Had anyone seen that field of battle, he would not repeat with such excitement and relish...
...To children ardent for some desperate glory,
The old Lie; Dulce et Decorum est
Pro patria mori.
No one who had seen this war could ever tell little boys stories of heroism and glory of war: for there was no glory, only horrific death. The quote that the title is based upon is translated as:
It is sweet and right to die for your country.
Owen is saying that it is not right or sweet. There is nothing noble about his war.
His intent, it would seem, was to reveal the lie for what it was, rather than let little boys believe the lie, so that they might one day find themselves believing it, only to finally face the truth, as he did, on a battlefield far from home.
**chloride of lime...was manufactured...during World War I, and used both as an irritant and as a lethal chemical during that conflict.